Ultrasound imaging is widely used in a range of medical applications. One area in which ultrasound imaging is used is to guide biopsy procedures. A biopsy typically involves identifying an abnormality of interest, such as suspicious solid mass, a distortion in the structure of a body tissue, or an area of abnormal tissue change. A needle or other fine member may be inserted into the abnormality and used to withdraw a small tissue sample for investigation.
Various types of needles may be used for biopsies. In fine needle aspiration, small hollow needles are used to extract cells from an abnormality. A core needle is a larger diameter needle which may be used to withdraw larger samples of tissue. Vacuum assisted devices may be used to collect multiple tissue samples during one needle insertion. In some cases ultrasound is used to assist in placing a guide wire into an abnormality to assist a surgeon in locating the abnormality for a surgical biopsy.
A problem with the use of ultrasound to guide a needle or wire in any of these procedures, or like procedures, is that the thin needles are often very difficult to see in an ultrasound image. This makes it difficult for a person taking the biopsy to ensure that the needle has reached its target. Also, guiding the needle to place the tip of the needle at an area of abnormality shown in an ultrasound image takes a significant amount of skill because the image does not always provide good feedback to the practitioner regarding exactly where the needle is placed and how the needle should be manipulated to cleanly enter the abnormality. Also, the needle may not be visible in the ultrasound image because the needle is out of the plane of the ultrasound image.
The following US patents and publications disclose technology in the general field of this invention:    U.S. Pat. No. 7,221,972 to Jackson et al.;    U.S. Pat. No. 5,161,536 to Vilkomerson et al.;    U.S. Pat. No. 6,216,029 to Palteili;    U.S. Pat. No. 6,246,898 to Vesely et al.;    U.S. Pat. No. 6,733,458 to Stein et al.;    U.S. Pat. No. 6,764,449 to Lee et al.;    U.S. Pat. No. 6,920,347 to Simon et al.;    2004/0267121 to Sarvazyan et al.;    WO 94/24933 to Bucholz;    WO 97/03609 to Paltieli;    WO 99/27837 to Paltieli et al.;    WO 99/33406 to Hunter et al.;    Freehand 3D Ultrasound Calibration: A Review, P-W. Hsu, R. W. Prager A. H. Gee and G. M. Treece CUED/F-INFENG/TR 584, University of Cambridge Department of Engineering, December 2007